A contender for the year's most depressing documentary, at least this film is sharply well made. It's also the first doc about the financial crisis that coherently helps us understand both what happened and what's going on now.

The film plainly explains how the financial craziness started with Reagan's deregulation in the 1980s, after which the investment houses started making increasingly huge short-term profits and enormous bonuses. Of course, this money had to come from somewhere, and it turns out that the bankers were knowingly stealing it from the people they were selling bad debt to all along. Warnings that a crash was coming started in 2004 but were ignored by the government regulators, and more than 30 million average-income people have lost jobs or homes as a result.

Using exhaustive research and extensive interviews, the film is lucid and riveting. Many interviewees speak with raw candour (some inject badly needed moments of humour), while the filmmakers fill in the story with news footage and strikingly clear graphics. Non-financially minded viewers will be surprised that they actually understand derivatives and credit default swaps, while Damon's able narration never condescends to us.

Simply put, these investment bankers are after personal gain at the expense of the public. So why aren't they in prison for money laundering, defrauding customers, conflict of interest and cooking their books? All of this is documented, but they're now either earning multi-million dollar bonuses at still-thriving financial institutions or working in the highest offices of government. After Reagan, both Bushes tilted the system to take money from the hard-working middle classes and give it to the most wealthy, while Clinton did nothing at all and Obama has only taken symbolic steps.

This isn't surprising when you know that all five presidents have hired Wall Street millionaires in key positions. As a result, America now has the largest disparity between rich and poor in the industrialised world, leading to economic chaos, crumbling education (people can no longer afford university) and an increasing housing crisis (as they can't buy homes). In other words, this is a film that gets our blood boiling in all the right ways. And it's not a polemic rant: it's a plain-speaking, journalistic document that's all too true.

Subtitled "a film for the future", this artful, sober-minded documentary is assembled as a message to the next generations: "We have buried something to protect you. Don't go in here." As a film, it's extremely mannered. And truly sobering.

The salient question is what we're doing with our nuclear waste. Existing storage systems require a power supply that won't last nearly long enough. The world above ground is unstable: there have been two world wars in the last century, so a permanent solution needs to be found. Conditions in the rock won't change, so the answer is a massive underground cave in Finland that's the size of a city. Called Onkalo, which means "hiding place", it won't be completed until the 22nd century and it needs to last for 100,000 years.

Slow almost to the point of paralysis, the film covers the reason why nuclear waste exists and why it has to be disposed properly. If it spills into nature, it would create areas that were uninhabitable ("Did that happen?" Madsen asks). The biggest fear for Onkalo is human intrusion. Would future generations interpret it as a burial ground or maybe a treasure? We can't predict the next hundred years, let alone the next thousand.

So how do we communicate to civilisations we can't imagine. Language and even alphabets are useless, but what about images like Munch's The Scream? Others argue that Onkalo should just be forgotten, because leaving a marker risks inciting curiosity. As this is so far beyond our imagination, it can't help but spark our ingenuity.

Once we adjust to the film's stilted, dreamy approach, it's a thoroughly unnerving experience. Shot and edited like a science-fiction movie, the film has a muted style that extends to the expert interviewees, glassy-eyed camera work and stark editing. It may be pretentious, but it's never academic. There's really only one point to make, but it's a mind-boggling one. Is it possible to isolate a place from humans (or any others) for this long? Think about it: the Egyptian pyramids were sealed just a few thousand years ago, never to be opened again. We know how that worked. And yet we still can't read some of their messages.

This thrillingly fast-paced documentary traces one family's struggle to find out how their famous son died as a soldier serving in Afghanistan. It's raw and honest, and utterly shocking from start to finish.

Pat Tillman was a millionaire 25-year-old football player when he and his brother Kevin enlisted in the US military in June 2002. During their first tour of duty in Iraq, they were assigned to the faked rescue of Jessica Lynch ("This war is so illegal," Pat wrote in response). A natural leader, Pat returned for his next tour in Afghanistan, where he was killed by friendly fire in April 2004. Instead of properly investigating his death, the Bush administration spun a false story for political gain.

Although the film never suggests it, the timing makes it fairly clear that Tillman's status as a celebrity soldier was used as part of Bush's 2004 re-election campaign. But filmmaker Bar-Lev expertly assembles the material with journalistic integrity, letting Tillman's family and friends tell the story as clearly as they can. And what it reveals about America's military and political world is pretty reprehensible. In other words, this is one of those docs that stirs a deep sense of righteous anger.

From the Lynch "rescue" to the policy banning footage of soldiers' coffins, the Bush administration "perception managed" this conflict for maximum propaganda value from day one. Tillman's death was painted as a heroic sacrifice, but his family and friends knew something wasn't adding up and, despite threats and obstruction, they tenaciously set out to correct the public record. Watching them doggedly sift through more than 3,000 pages of heavily redacted reports is seriously inspiring.

Bar-Lev tells the story through candid interviews, news clips, still images and powerful video footage. The big picture that emerges is so razor sharp that it's impossible to miss the point, although narrow-minded viewers might be distracted by the Tillmans' extremely colourful language and their fierce determination to avoid being painted as a typical, religious American family. But this is precisely what gives them credibility: they aren't trying to preach anything but the truth. "This isn't about Pat," says his mother Mary, "it's about what the government did to a nation."

This thoroughly involving documentary works on two levels: as a profile of an artist and as an exploration of human waste. And it's so cleverly assembled that it's entertaining and challenging at the same time.

Brazilian-born artist-photographer Vik Muniz lives and works in Brooklyn, creating artwork from unusual materials. Now he wants to do something that gives back to his subjects, so he travels to Rio de Janeiro to meet the "catadores" who collect recyclables in the world's largest dump, Jardim Gramacho. And as these people get involved in creating their own portraits out of materials they've gathered, everybody finds that their life is changing.

Filmmaker Walker and co-directors Joao Jardim and Karen Harley assemble a riveting narrative that connects with us on a variety of levels. We see the catadores telling their stories to Muniz, posing for photographs and then working as a team to transform reclaimed trash into magnificent mosaics. As their individual stories start tugging shamelessly on the heartstrings, we're moved by the honest reactions of these earthy, life-loving people.

And all of them have hilariously huge personalities. At the centre is the dynamic young leader Tiao, the pickers' union president. His journey is perhaps the most striking, as he travels to London for his portrait's auction. And Muniz gave him the US $50,000 it earned, plus another $200,000 from selling the other portraits.

To Muniz's surprise, the experience changed the catadores' lives more than the money did. And of course the project changes Muniz himself. This isn't just about the injustice of a class system that keeps people in poverty; it's about the power of the human spirit to survive and even thrive in challenging situations.

Walker assembles this with energy and style, following Muniz and the catadores through the entire process. She vividly captures the vast expanse of Jardim Gramacho from a deeply human perspective. And Moby's musical score adds a wonderful sense of life to the whole thing. And in the end we discover these things along with him, plus a realisation, along with Muniz, that the best way to help people is to give them dignity.